Why is my electrical cable getting hot inside the wall – Advice from Electriman, North London Electricians

Why Is My Cable Getting Hot Inside the Wall?

Finding that a cable or the area around a socket or switch feels warm — or smelling something burning from inside a wall — is a warning sign you must take seriously. Cables are designed to carry electricity safely without generating noticeable heat. When they do get hot, something is wrong.

What Causes Cables to Get Hot?

Overloaded circuit — Too many appliances drawing more current than the cable is rated for. The cable heats up just like a wire in an electric fire element.

Undersized cable — If a previous DIY job used cable that is too thin for the load it serves, it will overheat regularly.

Loose or poor connections — A badly terminated connection at a socket, junction box, or consumer unit creates high resistance at that point, generating localised heat.

Cable buried in insulation — Cables concealed in loft insulation or inside insulated walls cannot shed heat properly, reducing their current-carrying capacity significantly.

Damaged or degraded cable — Old rubber-insulated cables (pre-1960s) or cables that have been mechanically damaged can develop faults causing heating.

Sustained high load — Running high-draw appliances (electric showers, ovens, heaters) on circuits not designed for them.

What Should You Do Right Now?

1. Switch off the circuit at your consumer unit (fuse board) immediately.

2. Do not switch it back on

Need a qualified electrician in North London?

Electriman covers Mill Hill, Barnet, Finchley, Edgware, Enfield, Watford and surrounding areas. All work is Part P certified and fully insured.